Figure 4.30 | Adaptation constraints manifest across a range of dimensions and here are assessed based on a meta-review of water-related adaptation (Section 4.7.1, SM4.2, and Table SM4.5). Where less than five articles are available for assessment, data is insufficient to assess the extent to which a constraint is present. Where less than 20% of the articles reporting on the respective adaptation option identify the presence of a constraint, it is classified as ‘limited’, where 20 to 50% report on a specific constraint it is considered as ‘moderate’. Where more than 50% of articles report on the presence, the constraint is considered ‘significant’. This assessment is based on the available peer-reviewed literature assessing adaptation benefits in the water sector—in practice, these or other constraints may still be significant, but have not have been identified in peer-review sources.